参数资料
型号: MB9AF311MPMC
元件分类: 微控制器/微处理器
英文描述: 32-BIT, FLASH, 40 MHz, RISC MICROCONTROLLER, PQFP80
封装: 0.50 MM PITCH, PLASTIC, LQFP-80
文件页数: 18/114页
文件大小: 1357K
代理商: MB9AF311MPMC
ATmega48PA/88PA/168PA [DATASHEET]
9223F–AVR–04/14
114
The Timer/Counter overflow flag (TOV1) is set at the same timer clock cycle as the OCR1x registers are updated with the
double buffer value (at BOTTOM). When either OCR1A or ICR1 is used for defining the TOP value, the OC1A or ICF1 flag
set when TCNT1 has reached TOP. The interrupt flags can then be used to generate an interrupt each time the counter
reaches the TOP or BOTTOM value.
When changing the TOP value the program must ensure that the new TOP value is higher or equal to the value of all of the
compare registers. If the TOP value is lower than any of the compare registers, a compare match will never occur between
the TCNT1 and the OCR1x.
As Figure 16-9 shows the output generated is, in contrast to the phase correct mode, symmetrical in all periods. Since the
OCR1x registers are updated at BOTTOM, the length of the rising and the falling slopes will always be equal. This gives
symmetrical output pulses and is therefore frequency correct.
Using the ICR1 register for defining TOP works well when using fixed TOP values. By using ICR1, the OCR1A register is
free to be used for generating a PWM output on OC1A. However, if the base PWM frequency is actively changed by
changing the TOP value, using the OCR1A as TOP is clearly a better choice due to its double buffer feature.
In phase and frequency correct PWM mode, the compare units allow generation of PWM waveforms on the OC1x pins.
Setting the COM1x1:0 bits to two will produce a non-inverted PWM and an inverted PWM output can be generated by setting
the COM1x1:0 to three (See Table on page 117). The actual OC1x value will only be visible on the port pin if the data
direction for the port pin is set as output (DDR_OC1x). The PWM waveform is generated by setting (or clearing) the OC1x
register at the compare match between OCR1x and TCNT1 when the counter increments, and clearing (or setting) the OC1x
register at compare match between OCR1x and TCNT1 when the counter decrements. The PWM frequency for the output
when using phase and frequency correct PWM can be calculated by the following equation:
The N variable represents the prescaler divider (1, 8, 64, 256, or 1024).
The extreme values for the OCR1x register represents special cases when generating a PWM waveform output in the phase
correct PWM mode. If the OCR1x is set equal to BOTTOM the output will be continuously low and if set equal to TOP the
output will be set to high for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. If
OCR1A is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A output will toggle with a 50% duty
cycle.
16.10 Timer/Counter Timing Diagrams
The Timer/Counter is a synchronous design and the timer clock (clkT1) is therefore shown as a clock enable signal in the
following figures. The figures include information on when interrupt flags are set, and when the OCR1x register is updated
with the OCR1x buffer value (only for modes utilizing double buffering). Figure 16-10 shows a timing diagram for the setting
of OCF1x.
Figure 16-10.Timer/Counter Timing Diagram, Setting of OCF1x, no Prescaling
fOCnxPFCPWM
fclk_I/O
2N
×
TOP
×
-------------------------------
=
OCRnx - 1
clkI/O
(clkI/O/1)
TCNTn
OCRnx
OCFnx
clkTn
OCRnx
OCRnx Value
OCRnx + 1
OCRnx + 2
相关PDF资料
PDF描述
MSP430G2152IRSA16 16-BIT, FLASH, 16 MHz, RISC MICROCONTROLLER, PQCC16
M37704E2EFP 16-BIT, OTPROM, 16 MHz, MICROCONTROLLER, PQFP80
MSM65544-JS 8-BIT, MROM, 10 MHz, MICROCONTROLLER, PQCC68
MSM65516SS 8-BIT, MROM, 10 MHz, MICROCONTROLLER, PDIP64
MSM65P512JS 8-BIT, OTPROM, 10 MHz, MICROCONTROLLER, PQCC44
相关代理商/技术参数
参数描述
MB9AF312KPMC1-G-JNE2 功能描述:ARM? Cortex?-M3 FM3 MB9A310K Microcontroller IC 32-Bit 40MHz 160KB (160K x 8) FLASH 52-LQFP (10x10) 制造商:cypress semiconductor corp 系列:FM3 MB9A310K 包装:托盘 零件状态:有效 核心处理器:ARM? Cortex?-M3 核心尺寸:32-位 速度:40MHz 连接性:CSIO,I2C,LIN,UART/USART,USB 外设:DMA,LVD,POR,PWM,WDT I/O 数:36 程序存储容量:160KB(160K x 8) 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:16K x 8 电压 - 电源(Vcc/Vdd):2.7 V ~ 5.5 V 数据转换器:A/D 8x12b 振荡器类型:内部 工作温度:-40°C ~ 105°C(TA) 封装/外壳:52-LQFP 供应商器件封装:52-LQFP(10x10) 标准包装:160
MB9AF312KPMC-ES-E1 制造商:FUJITSU 功能描述:
MB9AF312KPMC-G-JNE1 制造商:FUJITSU 功能描述:
MB9AF312KPMC-G-JNE2 功能描述:ARM? Cortex?-M3 FM3 MB9A310K Microcontroller IC 32-Bit 40MHz 160KB (160K x 8) FLASH 48-LQFP (7x7) 制造商:cypress semiconductor corp 系列:FM3 MB9A310K 包装:托盘 零件状态:有效 核心处理器:ARM? Cortex?-M3 核心尺寸:32-位 速度:40MHz 连接性:CSIO,I2C,LIN,UART/USART,USB 外设:DMA,LVD,POR,PWM,WDT I/O 数:36 程序存储容量:160KB(160K x 8) 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:16K x 8 电压 - 电源(Vcc/Vdd):2.7 V ~ 5.5 V 数据转换器:A/D 8x12b 振荡器类型:内部 工作温度:-40°C ~ 105°C(TA) 封装/外壳:48-LQFP 供应商器件封装:48-LQFP(7x7) 标准包装:250
MB9AF312KQN-ES-AWE2 制造商:FUJITSU 功能描述: